Kodai Senga threw 15 pitches for Triple-A Syracuse, allowing no runs in one inning, walking one and striking out two.
The right-handed pitcher, who is recovering from a left calf injury, did not pitch the second inning after Syracuse's offense scored eight runs in a lengthy bottom of the first inning.
This was Senga's first, and likely only, rehab start.
He could return to the major leagues in the season finale series at Milwaukee, possibly as the opening pitcher.
J.D. Martinez, one of the best lefty killers of the past decade, was benched for the second time in four games against an opposing left-handed pitcher.
Martinez has gone 0-for-29 over his past eight games, his OPS has plummeted to .726 and he has been replaced at designated hitter by Starling Marte.
Manager Carlos Mendoza said the decision was the “result of a confluence of many factors,” including the fact that the afternoon game was played after an evening match.
But the biggest factor had to do with Martinez, the hired slugger, not the slugging.
“He's going through a tough time at the moment, it's tough,” Mendoza said of the 37-year-old, “but we have other players who are performing well.”
Martinez also watched from the dugout on Wednesday when the Mets faced Washington left-hander DJ Hurts.
Martinez has regularly performed well against left-handed pitching since his breakout 2014 season with the Tigers, posting a career OPS of .946.
But it's rare to see Martinez struggle like this, a rare display of ineffective hitting in a lineup that has been mostly lively this month.
No. 2 hitter Marte had an .880 OPS against left-handed pitchers this season, but was hitless in three at-bats and walked two.
Despite the absence, Martinez has largely continued to play despite his poor performance, and Mendoza suggested that will continue.
“He's a really good hitter, a professional hitter,” Mendoza said. “This isn't the first time he's had a slump like this. He's going to keep working on it. He's going to keep honing his craft. He's going to get better. He's a really good hitter.”
If the Mets don't adjust their starting rotation, Atlanta will have Jose Quintana, Luis Severino and David Peterson in that order.
The Mets could have Sean Manaea back on four days' rest and send Peterson out for their next series in Milwaukee.
“We're having that conversation right now,” Mendoza said, adding that there's a “possibility” that Peterson will start against the Braves.
Mendoza said he was “certain” that Paul Blackburn would miss the remainder of the regular season.
The right-hander has been pitching and conditioning since being diagnosed with a spinal fluid leak in his back last week.
But the series of bullpen sessions and play-by-play drills required before his return means that at least the regular season is complete.
“It's hard to set a timeline [on a return]”He pitched three good innings and two bad innings with the Mets, posting a 5.18 ERA,” Mendoza said of Blackburn.
Christian Scott is scheduled to undergo Tommy John elbow surgery with a medial brace on Monday.
